1. Field of the Invention
The present invention relates generally to video conferencing over a network. In particular, the present invention is directed towards synchronization and/or mixing of audio and video streams during a networked video conference call and for playback of recorded video conference calls.
2. Description of Background Art
Conventional networking software for video and audio conferencing permits one-way, two-way and in some cases multi-way communication between participants. Because each participant may be in a different environment and at a different location on a network, the transmission and reception of audio and video packets between various participants and/or to a central server may vary among them. For example, a participant may receive packets from a nearby participant in a more reliable fashion and with less delay than those from a participant that is more remotely located on the network. Packets may also be received out of order.
However transmitted and received over a network, audio and video data must be synchronized and mixed during display in order to produce a good video conferencing experience. For example, if the video and audio of a participant are not synchronized, then his mouth movements will not match his speech. The result can be annoying at best and can hinder communications at worst. Similarly, if the audio and/or video of different participants are not synchronized, then the unexpected pauses and timing may be interpreted as hesitations or other gestures. This can also hinder efficient communications between the participants.
Thus, there is a need for preferably simple approaches to synchronizing and mixing audio and/or video for networked participants in a video conference call.